Lint traps have been used for many years, being nylon bags, stockings, shredded aluminum traps, etc., being confined to drain tub applications only. However, it is apparent that the standpipe drain application has gone unaccommodated allowing sewer lines and septic systems to become restricted or blocked on occasions, resulting in unwanted drain cleaning expense.
In searching prior claims, U.S. Pat. No. 4,566,970 washing machine filter appeared to be nearest comparison; also not being of standpipe application.